Square D LLA36400U43X - 400 A, 3-Pole Plug-In Circuit Breaker | AmpState

Introducing the Square D LLA36400U43X — a 400A, 3-pole plug-in molded case circuit breaker built to shield panelboards and load centers from overcurrent and short circuits. Its fast plug-in connection minimizes install time and downtime during replacements, while the thermal-magnetic trip unit delivers stable, repeatable protection across varying loads and temperatures.

Designed for demanding environments, this breaker is compatible with matching OEM load centers and panelboards, ensuring seamless integration in residential, commercial, and light industrial applications.

• 400A, 3-pole plug-in molded case design: robust interrupting capability for large feeders and service panels.
• Fast plug-in connection: simplifies installation and quick replacement without special tools or field fabrication.
• Thermal-magnetic trip unit: provides reliable overload protection (thermal) and immediate short-circuit protection (magnetic), delivering consistent trip performance.
• Compatibility: engineered to fit OEM panelboards and load centers designed for plug-in breakers of this family and rating.
• Versatile across sectors: suitable for residential, commercial, and light industrial electrical systems, including data rooms, workshops, and small manufacturing setups.

Use cases and scenarios:

• Upgrade or replace aging or tripped breakers in a service or distribution panel where a 400A, three-pole protection is required.
• Install as part of a new main distribution panel serving large feeders or subpanels in commercial spaces, light industrial facilities, or electrical closets.
• Maintenance-friendly choice for facilities that prioritize quick swaps during panel servicing to minimize downtime.

Why choose this Square D breaker over alternatives:

• Plug-in mounting reduces field wiring and alignment hassles compared to bolt-on options, making service calls smoother.
• The thermal-magnetic trip curve delivers dependable performance in a wide range of loads, helping avoid nuisance trips while protecting equipment from damage.
• OEM compatibility means you can trust reliable panel integration and consistent trip characteristics with matching Square D products.

Practical notes for procurement and installation:

• Part number: LLA36400U43X
• Type: Thermal-magnetic molded case circuit breaker
• Application: Branch circuit overcurrent and short-circuit protection
• Mounting style: Plug-in

With the Square D LLA36400U43X, you get a high-capacity, plug-in protection solution that keeps critical circuits safeguarded and downtime minimal. Ready to install in compatible panelboards, this 3-pole breaker is a dependable choice for professionals who demand clarity, speed, and reliability in one package.